Method for preventing back flow in a dental saliva ejector

ABSTRACT

A unidirectional valve (46) is used for preventing a back flow (52) of fluid matter (72) in a dental saliva ejector (20). The unidirectional valve (46) includes a valve body (74) and a valve diaphragm (76). The valve diaphragm (76) is coupled to a base (78) of the valve body (74). The base (78) has apertures (90) for separating a particulate component (104) from a liquid component (102) of fluid matter (72). The valve diaphragm (76) has a flexible flap (96) for allowing a forward flow (48) of liquid component (102) into a low volume suction tube (28) of saliva ejector (20). The flexible flap (96) is further configured to prevent the back flow (52) liquid component (102) into an ejector tip (26) and into the mouth (22) of a dental patient (24).

TECHNICAL FIELD OF THE INVENTION

The present invention relates generally to the field of dentalinstruments, and specifically to the area of dental saliva ejectors. Inparticular, the present invention relates to a device for preventingback flow of fluid matter and oral contaminants in a dental salivaejector.

BACKGROUND OF THE INVENTION

A saliva ejector is an apparatus which includes a suction line and asaliva ejector tip. The saliva ejector tip is inserted into thepatient's mouth and suction is applied via the suction line to evacuatesaliva and other debris from the patient's mouth. Per convention, thesaliva ejector tip is a single use device that is replaced between eachpatient, while the suction line may be replaced or cleaned after it hasbeen used with several patients. Unfortunately, fluids from the previousdental patient or patients may remain in the suction line when thesaliva ejector is used on subsequent patients.

A common practice is to have patients close their lips around thelow-volume saliva ejector tip and "spit" to help evacuate the mouth.Closing the lips around the ejector tip can cause a decrease in thevacuum line pressure. This may allow the previously evacuated fluidremaining in the suction line to flow backwards, or back flow, into thepatient's mouth. This fluid can carry oral contaminants such as blood,viruses, bacteria, and fungi. It has been found that oral bacteria cansurvive inside of the suction line, and that diseases includinginfluenza, strep, and hepatitis B could be passed to subsequent patientsif the suction line back flows into the patient's mouth.

In order to decrease the possibility of the back flow of fluids into adental patient's mouth, dentists and hygienists may instruct theirpatients not to close their lips around the saliva ejector tips so as toprevent a decrease in the vacuum line pressure. However, a problemexists with this approach in that the saliva ejector tip may still getwedged in a position in the patient's mouth, for instance in the cheekfolds, to cause a decrease in the vacuum line pressure resulting in backflow.

Another approach for decreasing the chance of oral contaminants beingpassed from patient to patient is to clean or change the suction lineafter every patient. However, this approach is time consuming and costprohibitive. Furthermore, if the suction line is rinsed with a germkilling rinse, any remaining rinse residue in the suction line may backflow into a subsequent patient. This circumstance would be unpleasantfor the dental patient or possibly dangerous depending on the causticnature of the rinse.

In one prior art saliva ejector, the saliva ejector tip includes atleast one unregulated vacuum release aperture. This aperture is simply ahole made in a tubular sidewall of the ejector tip and is spaced fromthe mouthpiece of the saliva ejector tip such that when the mouthpieceis inserted into a patient's mouth, the patient's mouth will not blockthe aperture. If the patient's lips close around the mouthpiece, avacuum will not develop because air from the room will be drawn throughthe aperture. A problem with this device is that the fluid matter mayleak out of the aperture when the patient's mouth is being evacuatedwhich causes oral contaminants to be released into the room.

Another prior art device is a saliva ejector tip with an integral valve.The valve system is made up of an internal plunger in the end of theejector tip and is inserted into the patient's mouth. This plunger ispushed into a valve seat to close off the tip thereby eliminating thesucking noise produce by the saliva ejector. The dental personnel or thepatient can then close off the tip with a hand when the ejector tip isremoved from the mouth or the patient can close the valve using his orher teeth. Unfortunately, this device exacerbates the back flow problembecause this configuration intentionally causes a decrease in the vacuumline pressure which results in back flow.

Yet another prior art device is a valve which includes a chamber and atubular member positioned in the chamber. The tubular member has one ormore reversely lipped fins for providing a tortuous path to limit backflow of oral contaminants. However, a problem with this device is thatit does not prevent the back flow or oral contaminants, it merely limitsthe flow. Furthermore, due to the complex construction of this valve, itis difficult to clean and costly for single use applications.

SUMMARY OF THE INVENTION

Accordingly, an advantage of the present invention is that a valve andmethod for preventing back flow of fluid matter in a dental salivaejector are provided.

Another advantage of the present invention is that a valve and methodare provided that are readily incorporated into existing salivaejectors.

Yet another advantage of the present invention is that a valve isprovided that may be readily fabricated of inexpensive discardablematerial.

The above and other advantages of the present invention are carried outin one form by a unidirectional valve for preventing a back flow offluid matter in a dental saliva ejector. The saliva ejector has anejector tip and a low volume suction tube. The valve includes a valvebody located between the ejector tip and the low volume suction tube.The valve also includes a valve diaphragm coupled to a base of the valvebody. The valve diaphragm is configured to allow a forward flow of thefluid matter from the ejector tip to the low volume suction tube and toprevent the back flow of the fluid matter from the suction tube to theejector tip.

The above and other advantages of the present invention are carried outin another form by a unidirectional ejector tip for preventing a backflow of fluid matter in a dental saliva ejector that has a low volumesuction tube. The ejector tip includes an ejector tube configured toreceive the fluid matter from the mouth of a patient. An interfacingsocket has a first end configured to retain the ejector tube and asecond end configured to retain the low volume suction tube. Theinterfacing socket has an inner shoulder and an axially aligned socketchannel through the inner shoulder. A unidirectional valve is coupled tothe inner shoulder of the interfacing socket. The unidirectional valveis configured to allow a forward flow of the fluid matter from theejector tube through the socket channel into the low volume suctiontube. The valve is further configured to prevent the back flow of thefluid matter from the suction tube into the ejector tube.

BRIEF DESCRIPTION OF THE DRAWINGS

A more complete understanding of the present invention may be derived byreferring to the detailed description and claims when considered inconnection with the Figures, wherein like reference numbers refer tosimilar items throughout the Figures, and:

FIG. 1 shows dual views of a saliva ejector in the mouth of a patient;

FIG. 2 shows a perspective view of a saliva ejector with aunidirectional valve located therein;

FIG. 3 shows a sectional view of the saliva ejector;

FIG. 4 shows the base of a valve body that forms part of theunidirectional valve;

FIG. 5 shows a side view of a valve diaphragm that forms part of theunidirectional valve;

FIG. 6 shows a side view of a unidirectional valve in an open position;and

FIG. 7 shows a side view of the unidirectional valve in a closedposition; and

FIG. 8 shows a unidirectional ejector tip in an alternate embodiment ofthe present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 1 shows dual views of a saliva ejector 20 in the mouth 22 of adental patient 24. Saliva ejector 20 includes an ejector tip 26configured to be placed in mouth 22. Saliva ejector 20 also includes asuction tube 28 whose lower end (not shown) is connected to a low volumevacuum source (not shown). During a dental procedure, ejector tip 26 isinserted into mouth 22 to remove by suction any saliva and smallparticles, such as excess filling material, ground-away old fillings,decay, and so forth.

Patient 24 is depicted in two scenarios. In a first scenario 30, patient24 is a patient 24' with mouth 22 in an open position 32. When the lowvolume vacuum source (not shown) is activated, a first differentialpressure 34 results in suction tube 28. First differential pressure 34is less than the ambient pressure at ejector tip 26 in mouth 22,therefore a forward flow occurs in the direction shown by an arrow 36 toevacuate mouth 22 of fluid matter (not shown).

Patient 24 is depicted in a second scenario 38 to illustrate back flowin saliva ejector 20. In second scenario 38, patient 24 is a patient 24"with mouth 22 in a closed position 40. When mouth 22 is closed and theaspirator holes (not shown) in ejector tip 26 are blocked, a seconddifferential pressure 42 results in ejector tip 26. Second differentialpressure 42 is less than the pressure in suction tube 28, thereforewithout the incorporation of the present invention, a back flow of fluidmatter may occur in the direction shown by an arrow 44 to eject fluidmatter into mouth 22.

FIG. 2 shows a perspective view of saliva ejector 20 with aunidirectional valve 46 incorporated therein. Valve 46 allows a forwardflow 48 of fluid matter (discussed below) from an ejector tube portion50 of ejector tip 26 into low volume suction tube 28 and prevents a backflow 52 of fluid matter (not shown) from suction tube 28 into tubeportion 50 of ejector tip 26.

In the preferred embodiment, saliva ejector 20 includes an interfacingsocket 54. Interfacing socket 54 has a first end 56 and a second end 58.First end 56 is configured to retain ejector tip 26 by press fittingejector tip 26 into first end 56.

Saliva ejector 20 also includes a suction controller 60. Suctioncontroller 60 has a third end 62 and a fourth end 64. Third end 62 isconfigured to retain suction tube 28 by press fitting suction tube 28onto a stem (not shown). Fourth end 64 of suction controller 60 mateswith second end 58 of interfacing socket 54 either by press fittingtogether or by threaded engagement where both fourth and second ends 64and 58 have coupling threads internally and externally, respectively.

Suction controller 60 is configured to allow the vacuum source (notshown), which produces first differential pressure 34 (FIG. 1), to drawfluid matter from ejector tip 26. The suction is controlled by adjustinga lever 66 on suction controller 60. Unidirectional valve 46 is locatedwithin interfacing socket 54 and suction controller 60 at the locationwhere second end 58 and fourth end 64 mate.

FIG. 3 shows a sectional view of saliva ejector 20. Interfacing socket54 has an axially aligned socket channel 68 passing from first end 56through an inner shoulder 69 of interfacing socket 54 and through secondend 58. Likewise, suction controller 60 has an axially alignedcontroller channel 70 passing from fourth end 64 through third end 62.Unidirectional valve 46 is located in socket channel 68 and controllerchannel 70 between ejector tip 26 and low volume suction tube 28 (FIG.2) to form a passage through which fluid matter 72 passes.Unidirectional valve 46 includes a valve body 74 and a valve diaphragm76.

Referring collectively to FIGS. 4-7, FIG. 4 shows a base 78 of valvebody 74 that forms part of unidirectional valve 46. FIG. 5 shows a sideview of valve diaphragm 76 that forms part of unidirectional valve 46.FIG. 6 shows a side view of unidirectional valve 46 in an open position80. Finally, FIG. 7 shows a side view of unidirectional valve 46 in aclosed position 82.

Valve body 74 has a retaining end 84 which is configured to be coupledto inner shoulder 69 (FIG. 3) of interfacing socket 54 (FIG. 3). Base 78of valve body 74 exhibits a base diameter 86. Valve body 74 isconfigured to fit in socket and controller channels 68 and 70,respectively (FIG. 3). Base 78 has a central opening 88 and a pluralityof apertures 90. Central opening 88 exhibits an inner diameter 92.

Valve diaphragm 76 includes a shaft 94 and a flexible flap 96. Shaft 94has a retaining collar 98 which exhibits an outer diameter 100. Outerdiameter 100 is greater than inner diameter 92 of central opening 88 inbase 78. This configuration allows shaft 94 to be passed through centralopening 88 such that retaining collar 98 is forced through centralopening 88, to retain shaft 94 in central opening 88.

Flexible flap 96 exhibits a flap diameter 97 that is no greater thanbase diameter 86. Additionally, unidirectional valve 46 is located insocket and controller channels 68 and 70, respectively, such thatflexible flap 96 of valve diaphragm 76 is free to flex to open position80 and closed position 82.

Flexible flap 96 is configured to flex to open position 80 relative tobase 78 in response to first differential pressure 34 (FIG. 1) presentin low volume suction tube 28 (FIG. 1) to allow passage of fluid matter72 through ejector valve 46. Flexible flap 96 is further configured toflex to closed position 82 in response to second differential pressure42 (FIG. 1) present in ejector tip 26 (FIG. 1).

Fluid matter 72 from mouth 22 (FIG. 1) includes a liquid component 102,such as saliva, water, and blood, and a particulate component 104, suchas excess filling material, ground-away old fillings, and decay. Whenflexible flap 96 is in open position 80, apertures 90 (FIG. 4) locatedin base 78 allow forward flow 48 of liquid component 102 into suctiontube 28 and retain particulate component 104 in valve body 74. Whenflexible flap 98 is in closed position 82, back flow 52 of liquidcomponent 102 is prevented, thus preventing liquid component 102 andparticulate component 104 from flowing back through ejector tip 26 andinto mouth 22 (FIG. 1).

Unidirectional valve 46 is formed from plastic materials. For example,valve body 74 is formed from a stiff, strong resin type plastic andvalve diaphragm is formed from a flexible rubber material such as vinylor silicon. These materials are inexpensive and easily manufactured, sothat valve 46 is readily discardable after a single use. Furthermore,unidirectional valve 46 is sized to fit into conventional salivaejectors in place of the filter basket typically found between theejector tip and the low volume suction tube. Therefore, unidirectionalvalve 46 is readily incorporated into existing saliva ejector systemsand can be replaced between each dental patient at the same time thatejector tip 26 (FIG. 2) is being replaced so that the back flow of oralcontaminants between dental patients is easily and inexpensivelyprevented.

FIG. 8 shows a unidirectional ejector tip 106 in an alternate embodimentof the present invention. Unidirectional ejector tip 106 prevents theback flow of fluid matter 72 in a dental saliva ejector 20 (FIG. 1).Unidirectional ejector tip 106 includes an ejector tube 108, aninterfacing socket 110, and a unidirectional valve 112 formed as asingle unit.

Like saliva ejector 20 (FIG. 3), ejector tube 108 is configured toreceive fluid matter 72 from mouth 22 (FIG. 1) of patient 24 (FIG. 1).Interfacing socket 110 has a first end 56 configured to retain ejectortube 108, a second end 58 configured to retain low volume suction tube28 (FIG. 1), and an inner shoulder 69. Interfacing socket 110 has anaxially aligned socket channel 68 through inner shoulder 69. Interfacingsocket 110 exhibits the features of interfacing socket 54 (FIG. 3) andwill not be described in detail herein.

Unidirectional valve 112 is coupled to inner shoulder 69 of interfacingsocket 110. Valve 112 is configured to allow a forward flow of fluidmatter 72 from ejector tube 108 through socket channel 68 into lowvolume suction tube 28. Valve 112 also prevents back flow of fluidmatter 72 from suction tube 28 into ejector tube 108. Unidirectionalvalve 112 exhibits the features of unidirectional valve 46 and will notbe described in detail herein.

Unidirectional ejector tip 106 is configured to connect to suctioncontroller 60, which is a semi-permanent component generally made ofautoclaveable stainless steel, of saliva ejector 20. Unidirectionalejector tip 106 is formed from plastic materials such that theunidirectional ejector tip is readily replaceable after a single use.

A method for preventing the back flow of fluid matter containing liquidand particulate into the mouths of each of a plurality of dentalpatients undergoing a dental procedure includes the following steps. Themethod includes allowing the flow of fluid matter 72 in a firstdirection, or forward flow 48, through unidirectional valve 46 of salivaejector 20. Particulate component 104 is separated from liquid component102 in base 78 of valve body 74. Liquid component 102 is then ejectedthrough low volume suction tube 28. Flow of liquid component 102 isprevented in a second direction, or back flow 52, by the closure offlexible flap 96 in response to second differential pressure 42 (FIG.1). Finally, unidirectional valve 46 or unidirectional ejector tip 106with the integral unidirectional valve 112 is replaced between each ofthe patients in order to remove particulate component 104 that wasseparated from fluid component 102 in base 78.

In summary, the present invention provides a unidirectional valve and amethod for preventing the back flow of fluid matter containing oralcontaminants in a dental saliva ejector. Furthermore, the unidirectionalvalve is readily incorporated into conventional saliva ejectors. Inaddition, the unidirectional valve is readily fabricated of inexpensivematerial so that the unidirectional valve is a disposable, single usecomponent of the saliva ejector.

Although the preferred embodiments of the invention have beenillustrated and described in detail, it will be readily apparent tothose skilled in the art that various modifications may be made thereinwithout departing from the spirit of the invention or from the scope ofthe appended claims. For example, the unidirectional valve may coupledirectly to the low volume suction valve instead of the suctioncontroller as described.

What is claimed is:
 1. A method for preventing a back flow of fluid matter from a dental saliva ejector into the mouths of each of a plurality of dental patients undergoing a dental procedure, said fluid matter having a liquid component and a particulate component, said dental saliva ejector having a unidirectional valve, and said method comprising the steps of:allowing flow of said fluid matter in a first direction; separating said particulate component from said liquid component; ejecting said liquid component; preventing flow of said liquid component in a second direction, said second direction being a direction for said back flow; and replacing said unidirectional valve between each of said patients to remove said particulate component separated in said separating step.
 2. A method as claimed in claim 1 wherein said unidirectional valve includes a flexible flap, said flap flexing to an open position in response to said allowing step and said flap flexing to a closed position in response to said preventing step. 